fix: add process shim for Node.js libraries in browser context

Inject a minimal process shim via esbuild to resolve "process is not
defined" errors from nostr-crypto-utils transitive deps (crypto-browserify,
readable-stream, etc.) in Chrome MV3 service worker.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: vveerrgg

build.js

@@ -34,6 +34,10 @@ const chromeEntryPoints = {
 
 const shared = {
     bundle: true,
+    inject: [`${SRC}/shims/process.js`],
+    define: {
+        'global': 'globalThis',
+    },
     plugins: [{
         name: 'node-module-stubs',
         setup(build) {

src/shims/process.js

@@ -0,0 +1,17 @@
+/**
+ * Minimal process shim for browser context.
+ * Node.js libraries bundled via nostr-crypto-utils (crypto-browserify,
+ * readable-stream, etc.) reference the global `process` object.
+ * This provides just enough for them to work in a browser extension.
+ */
+export var process = {
+    env: { NODE_ENV: 'production', LOG_LEVEL: 'warn' },
+    browser: true,
+    version: '',
+    stdout: null,
+    stderr: null,
+    nextTick: function (fn) {
+        var args = Array.prototype.slice.call(arguments, 1);
+        Promise.resolve().then(function () { fn.apply(null, args); });
+    },
+};